Bob - not familiar with that particular iron, looks kind of nice though. Not a bad price either, has interchangeable tips.

As for temperature, it depends on three things (simplistically) 1) how well your iron's tip carries the heat, 2) the size of the item to be heated, and 3) how fast you wet the joint after it is ready.

That board has through holes. I would tin the wires before putting them in the holes (strip and wet with solder and then let cool, trim any draw spikes before inserting in holes). 031 is maybe a little big, but just use it sparingly. Tinning the wire helps a whole bunch in the process, just make sure you wet the pad nicely, you'll see it when it happens.

As for temp, for the thinnest of wires, I would start at 600F (315C) and try one. The 031 solder might take a little more heat to wet. Make sure the iron tip is contacting the pad and the wire and hit the joint in the middle. Remember that the rosin is the cleaning agent which lets the solder adhere - once you see smoke, it is doing its thing. If the joint doesn't solder real quick, bump up the temp.

If the wire is really big (like bus bar type wiring) you need to compensate for the need for the tip to recover temperature, so the temp might need to be even higher. If you heat the joint and it takes 10 seconds for the temp to recover, then you need a bigger mass at the tip or an iron with quicker recovery or more power.

Rick, I am KISS proponent, and strive to do things the easiest way, they get done quicker that way, this is my first Deltang fit, the body is of a local Australian prototype which is a lot smaller than American diesels (H0 scale) so space was a premium.
But back to Keep It Simple S#$#@d, the RX62 with its built in Reed switch (which actually had to be soldered on, that is not ready fitted from Deltang) is mounted on the arm hanging out to the front over the gearbox, this puts the reed switch up high for easier activation by the magnet. The box to the rear holds the 2x 450mA batteries given the 7.6 volts, the battery lead has a plug (the only one, remember, minimal space!) in case I need to remove the batteries, I don't have to for charging, so everything is hard wired. 3 very thin wires go down to the 3 sockets you can see above the fuel tank which is the charging 'port', other photos show the charging lead and charger that I plug into the socket for charging, I have it set up so the plug can only go in one way, you don't want to reverse that wiring for charging batteries! I can also check the battery voltage with the charging lead. The charging wires go to the back of the battery plug, the 2 power wires to the Deltang board also go to the back of the plug. No change over switch or anything fancy, I have even left the RX turned on while charging, no damage done. I have used 3 small wires, all the same size for charging, no problems at all, the wires are about the same size that manufacturers use on the LiPo batteries, they must have it right!
I have also played around with fitting an RX60 to a NMRA DCC plug so I can plug this into any DCC plugged loco and plug the battery pack into that, I run this set up in a couple of different steamers at friends layouts.
I balance charge and get many hours of running out of the batteries.

Not a bummer at all......
In most installations the reed switch needs to be at a different location/position than the receiver board. The value of the RX62 board is the built in circuit that the reed switch triggers. I would not want to have to unsolder a reed switch from the board to relocate it.

Yes, I was a bit miffed when I recieved the RX62 as well Rick, but it isn't a big deal to solder the reed switch on, from memory there is an orientation thing to comply with.But it's all in the wording as well, the RX20 does come with a built in e switch, that is the 'latch on latch off' switch built into the board that is activated by the momentary contact of the reed switch, I haven't tried it yet but I am thinking that the e switch could be activated by a momentary contact push button. The task of soldering the reed switch on is worth it for the convenience of use.I have glued a magnet to the top of my TX22 box so I can just wave it on and turn it off by holding the bind button down for 10 seconds, excellent.I haven't done so yet but I will eventually wire my headlights to the RX62 so headlights will alway be on while the RX is on.Wayne from Oz